To implement an approach final phase on an airport, the crew of an aircraft, particularly of a transport aircraft, has to indicate to the on-board systems the particular final approach that has to be followed, amongst a plurality of different approaches being possible. The cockpits of the aircrafts include a flight management system, of the <<FMS>> (<<Flight Management System>>) type, that represents a man-machine interface generally allowing the crew to select the final approach. When such selection is performed, the on-board systems automatically coordinate to allow the aircraft to fly according to the selected final approach.
It is known that the air-traffic controllers can recommend a specific approach, particularly that use the most efficient approach aid means provided on board the aircraft or the one that is available according to planned maintenance and traffic actions, as well as meteorology. The pilot can select an approach different from that recommended, for instance if an on-board equipment the use of which is necessary for this recommended approach is out of service or if he/she wants to train him/herself to perform an other approach (with the proviso that the meteorological conditions allow it).
To select a final approach, the crew has to consult the usual approach charts (paper or electronic format). On these approach charts, the final approaches are characterized by their type (precision, no precision), the guiding device being used, and the minimal decision heights being allowed. The selection of a final approach also relies on the aircraft ability to technically implement such approach, including the equipment provided on board the aircraft and their running state.
Thus, the aircraft crew selects the final approach based on the approach charts they have in their possession, on the information given by the air-traffic controller and on the state of the on-board systems, as well as on weather, which results in an important workload. With the increasing use of GNSS (<<Global Navigation Satellite System>> technologies) such as the GPS constellation and the Galileo constellation, as well as their increases such as the SBAS, GBAS or ABAS systems, as defined by the appendix 10 OACI (International Civil Aviation Organisation) in the field of the aeronautic navigation and the arrival of new technologies as a MLS system, the number of possible approaches is still growing.
Within the scope of the present invention, the following precision approach procedures can for instance be taken into account:                an instrument approach procedure, relating to an instrument landing system, for instance of the ILS (<<Instrument Landing System>>) type, such as described for instance in patent FR-2,852,685;        an instrument approach procedure, relating to a microwave landing system, for instance of the MLS (<<Microwave Landing System>>) type; and        an instrument approach procedure, relating to a GPS (<<Global Positioning System>>) landing system of the GLS (<<GBAS Landing System>>) type.        
Moreover, a non precision approach procedure of the RNAV type can be flown with either the SLS (<<Satellite Landing System>>) or FLS (<<FMS Landing System>>) function. The FLS function is for instance described in patents FR-2,852,683, FR-2,852,684 and FR-2,852,686.
The final approach selection thus requires from the crew to perform a number of actions, the number of which grows, as the number of available approaches on a ground increases, which induces a growing workload.
The present invention aims to overcome such drawbacks. It relates to a method for aiding the piloting of an aircraft during an approach final phase, which allows the workload of the aircraft crew to be reduced and to bring at least a partial automation and thus to favourably act on the aircraft safety.